Electrode for plasma processing apparatus, plasma processing apparatus, plasma processing method and storage medium

ABSTRACT

The present invention provides an upper electrode used in an etching apparatus and the etching apparatus including the upper electrode, both of which can properly reduce intensity of electric field of plasma around a central portion of a substrate to be processed, thus enhancing in-plane uniformity of a plasma process. In this apparatus, a recess, serving as a space for allowing a dielectric to be injected therein, is provided around a central portion of the upper electrode. A dielectric supply passage configured for supplying the dielectric into the space and a dielectric discharge passage configured for discharging the dielectric from the space are connected with the space, respectively. With such configuration, the dielectric can be controllably supplied into the recess, such that in-plane distribution of the intensity of the electric field can be uniformed, corresponding to in-plane distribution of the intensity of the electric field of the plasma generated under various process conditions, such as a kind of each wafer that will be etched, each processing gas that will be used, and the like.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on the prior Japanese Patent Application No.2008-50745 filed on Feb. 29, 2008 and U.S. Provisional PatentApplication No. 61/71556 filed on May 6, 2008, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an upper electrode, a table (or lowerelectrode), a plasma processing apparatus including at least one of theupper electrode and table, a plasma processing method and a storagemedium, each used for processing a substrate to be processed, such as asemiconductor wafer or the like, to which a plasma process is provided.

2. Background Art

In a step for manufacturing semiconductor devices, for example, a dryetching process, an ashing process and the like has been known, as theplasma process for processing the substrate by changing a processing gasinto plasma. In an etching apparatus for performing the dry etchingprocess, for example, a pair of parallel and flat electrodes arevertically arranged to be opposed to each other. By application of highfrequency electric power to a space between the two electrodes, theprocessing gas introduced into the space can be changed into the plasma.As a result, the substrate to be processed, such as the semiconductorwafer (hereinafter referred to as “the wafer”) or the like, which isplaced on the lower electrode, can be subjected to the etching process.For example, as the etching process, a process for forming recesses in afilm formed on the wafer, by using a resist pattern, as a mask, providedon the film to be etched, has been known.

In recent years, a “lower energy and higher density” process, requiringlower ion energy in the plasma and higher electron density, has beenwidely used in the plasma process. For instance, in the case of etchinga silicon film or any other organic film, properly high frequencyelectric power is generally applied to the electrode provided on a lowerside, in order to generate higher density plasma and suppressintroduction or capture of ions into the wafer.

In some cases, for the generation of such lower energy and higherdensity plasma, an extremely high frequency, e.g., 100 MHz, of the highfrequency electric power should be required, as compared with thefrequency (e.g., approximately several ten MHz) that has been employedso far. However, such an extremely high frequency of the electric powerapplied to the apparatus may tend to considerably increase intensity ofan electric field around a central portion of a surface of theelectrode, i.e., a region corresponding to a central portion of thewafer, while relatively decreasing the intensity of the electric fieldaround the periphery of the wafer. Therefore, as shown in FIG. 16, theetching process is progressed at a higher rate around the centralportion of the wafer, while exhibiting a significantly lower etchingrate around the periphery of the wafer.

To address such problems, Patent Documents 1 and 2 disclose improvedetching apparatuses, respectively. Each of these apparatuses is intendedfor enhancing in-plane uniformity of the plasma process, by embedding adielectric in a region around the central portion of the upperelectrode, such that distribution of the electric field can made uniformby the dielectric. In fact, such an etching apparatus is suitable forproviding the plasma process to each wafer having the same layeredstructure under the same conditions. In some cases, however, the etchingprocess should be provided to different wafers, such as those havingdifferent films to be etched and/or different kinds of resist patternfilms formed thereon.

Additionally, although having the same layered structure, each wafersometimes has the resist pattern formed thereon with a different shapeand/or is sometimes designed to have the recesses each formed in thefilm while having a different aspect ratio (i.e., a ratio of a depth ofthe recess relative to a diameter of an opening thereof).

In such a case, the process conditions, such as a kind and/or pressureof each processing gas used, each value of the high frequency electricpower and the like, should be controlled, corresponding to a kind or thelike of each wafer. Therefore, the state or condition of the plasmashould also be changed with such control of the process conditions.Thus, for enhancing the in-plane uniformity of the plasma process, it isnecessary to control the distribution of the electric field,corresponding to the process conditions. However, in the etchingapparatus having the dielectric provided in the upper electrode asdisclosed in the above Patent Documents, the dielectric should beexchanged with another one, such as by disassembling the apparatus, inorder to control the distribution of the electric field. This makes itsubstantially difficult to optionally control the distribution of theelectric field, corresponding to the process conditions.

Patent Document 3 describes a technique for controlling a relativepermittivity, by providing a control part formed from a dielectricmaterial, between a chamber body and a first electrode. Morespecifically, the control part has a tank-like structure providedtherein, such that a material that can optionally control the relativepermittivity can be supplied into the tank-like structure. Thisconfiguration is only aimed to control the equivalent relativepermittivity, by controlling a degree of electrical connection betweenthe first electrode and the grounded chamber body. Accordingly, thistechnique cannot solve the above problems in nature.

Patent Document 1: JP2000-323456A (Paragraph [0049], FIG. 4)

Patent Document 2: JP2005-228973A (Paragraphs [0030] to [0033], FIG. 1)

Patent Document 3: JP2007-48748A (Paragraph [0038], FIGS. 3 to 5)

SUMMARY OF THE INVENTION

The present invention was made in light of the above circumstances, andtherefore it is an object of this invention to provide a new upperelectrode and/or table (or lower electrode), which is used for theplasma processing apparatus and adapted for providing the plasma processto the substrate or wafer with higher in-plane uniformity, by enhancingthe in-plane uniformity of the intensity of the electric field of theplasma, with a simple structure, corresponding to the processconditions. Another object of this invention is to provide an improvedplasma processing apparatus including at least one of the upperelectrode and table related to this invention, a plasma processingmethod using this plasma processing apparatus, and a storage medium forstoring this plasma processing method therein.

The present invention is an electrode for use in a plasma process,wherein the electrode is provided to be opposed to a lower electrode onwhich a substrate is placed in a processing space, wherein highfrequency power is supplied to a space between the electrode and thelower electrode, so as to generate plasma therein and perform the plasmaprocess to the substrate, and wherein the electrode comprises: anelectrode plate provided to be opposed to the lower electrode; a supportmember provided opposite to the lower electrode across the electrodeplate, configured for supporting the electrode plate, and having adielectric injection space formed therein such that a dielectric usedfor controlling intensity of an electric field in the processing spacecan be injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of the supportmember via a dielectric supply passage and configured for supplying thedielectric into the dielectric injection space; and a dielectricdischarge passage connected with the dielectric injection space of thesupport member and configured for discharging the dielectric from thedielectric injection space.

In the electrode for use in the plasma process according to the presentinvention, the dielectric injection space of the support member isprovided along a face on the side of the electrode plate of the supportmember.

In the electrode for use in the plasma process according to the presentinvention, a member having a gas diffusion space formed therein isprovided, the gas diffusion space being connected with a processing gassupply source configured for supplying a processing gas to thesubstrate, wherein a plurality of gas discharge ports are provided onthe electrode plate, each of the gas discharge ports being incommunication with the gas diffusion space and configured for injectingthe processing gas into the processing space, like a shower.

In the electrode for use in the plasma process according to the presentinvention, the member having the gas diffusion space formed therein isalso used as the electrode plate or used as the support member.

In the electrode for use in the plasma process according to the presentinvention, the member having the gas diffusion space formed therein isprovided between the electrode plate and the support member.

In the electrode for use in the plasma process according to the presentinvention, the member having the gas diffusion space formed therein isformed from a dielectric having a relative permittivity within a rangeof 1 to 10.

In the electrode for use in the plasma process according to the presentinvention, a gas supply member is provided to be projected downward froma central portion of the electrode plate, the gas supply member having adome-like shape and a plurality of gas discharge apertures formedtherein, each of the gas discharge apertures being configured forinjecting the processing gas into the processing space.

In the electrode for use in the plasma process according to the presentinvention, a temperature control mechanism adapted for controlling thetemperature of the support member is provided to the support member.

Alternatively, the present invention is an electrode for use in a plasmaprocess, wherein the electrode is provided to be opposed to an upperelectrode in a processing space, wherein high frequency power issupplied to a space between the electrode and the upper electrode, so asto generate plasma therein and perform the plasma process to a substrateplaced on one face of the electrode, and wherein the electrodecomprises: an electrode member provided to be opposed to the upperelectrode, a dielectric-injection-space-constituting member having adielectric injection space formed therein such that a dielectric usedfor controlling intensity of an electric field in the processing spacecan be injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of thedielectric-injection-space-constituting member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space and configured for discharging the dielectricfrom the dielectric injection space.

In the electrode for use in the plasma process according to the presentinvention, the dielectric injection space is provided in a positioncorresponding to a central portion of the substrate.

In the electrode for use in the plasma process according to the presentinvention, the dielectric discharge passage is connected with thedielectric supply source, such that the dielectric can be circulatedbetween the dielectric injection space and the dielectric supply source.

The electrode for use in the plasma process according to the presentinvention, further comprises a storage unit adapted for storing thereindata correlating a kind of each process with an injection amount of thedielectric into the dielectric injection space, and a means adapted forreading the injection amount of the dielectric corresponding to the kindof each selected process from the storage unit then controlling theinjection amount of the dielectric.

Alternatively, the present invention is a plasma processing apparatusincluding an upper electrode, a table constituting a lower electrode,and a processing vessel having a processing space containing the upperelectrode and the lower electrode therein, the plasma processingapparatus comprising: a first high frequency power source connected withthe lower electrode and used for generating plasma; a gas supply passageconfigured for supplying a processing gas into the processing vessel;and a vacuum exhaust means adapted for evacuating the interior of theprocessing vessel, wherein the upper electrode comprises: an electrodeplate provided to be opposed to the lower electrode; a support memberprovided opposite to the lower electrode across the electrode plate,configured for supporting the electrode plate, and having a dielectricinjection space formed therein such that a dielectric used forcontrolling intensity of an electric field in the processing space canbe injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of the supportmember via a dielectric supply passage and configured for supplying thedielectric into the dielectric injection space; and a dielectricdischarge passage connected with the dielectric injection space of thesupport member and configured for discharging the dielectric from thedielectric injection space.

Alternatively, the present invention is a plasma processing apparatusincluding an upper electrode, a table constituting a lower electrode,and a processing vessel having a processing space containing the upperelectrode and the lower electrode therein, the plasma processingapparatus comprising: a first high frequency power source connected withthe lower electrode and used for generating plasma; a gas supply passageconfigured for supplying a processing gas into the processing vessel;and a vacuum exhaust means adapted for evacuating the interior of theprocessing vessel, wherein the lower electrode comprises: an electrodemember provided to be opposed to the upper electrode, wherein at leastone of the first high frequency power source for generating the plasmaand a second high frequency power source for introducing ions present inthe plasma is connected with the electrode member; adielectric-injection-space-constituting member having a dielectricinjection space formed therein such that a dielectric used forcontrolling intensity of an electric field in the processing space canbe injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of thedielectric-injection-space-constituting member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space and configured for discharging the dielectricfrom the dielectric injection space.

Alternatively, the present invention is a plasma processing apparatusincluding an upper electrode, a table constituting a lower electrode,and a processing vessel having a processing space containing the upperelectrode and the lower electrode therein, the plasma processingapparatus comprising: a first high frequency power source connected witheither one of the upper electrode and lower electrode and used forgenerating plasma; a second high frequency power source connected withthe lower electrode and used for introducing ions present in the plasma;a gas supply passage configured for supplying a processing gas into theprocessing vessel; and a vacuum exhaust means adapted for evacuating theinterior of the processing vessel into a vacuum state, wherein the upperelectrode comprises: an electrode plate provided to be opposed to thelower electrode; a support member provided opposite to the lowerelectrode across the electrode plate, configured for supporting theelectrode plate, and having a dielectric injection space formed thereinsuch that a dielectric used for controlling intensity of an electricfield in the processing space can be injected into the dielectricinjection space; a dielectric supply source connected with thedielectric injection space of the support member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space of the support member and configured fordischarging the dielectric from the dielectric injection space.

Alternatively, the present invention is a plasma processing apparatusincluding an upper electrode, a table constituting a lower electrode,and a processing vessel having a processing space containing the upperelectrode and the lower electrode therein, the plasma processingapparatus comprising: a first high frequency power source connected witheither one of the upper electrode and the lower electrode and used forgenerating plasma; a second high frequency power source connected withthe lower electrode and used for introducing ions present in the plasma;a gas supply passage configured for supplying a processing gas into theprocessing vessel; and a vacuum exhaust means adapted for evacuating theinterior of the processing vessel, wherein the lower electrodecomprises: an electrode member provided to be opposed to the upperelectrode, a dielectric-injection-space-constituting member having adielectric injection space formed therein such that a dielectric usedfor controlling intensity of an electric field in the processing spacecan be injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of thedielectric-injection-space-constituting member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space and configured for discharging the dielectricfrom the dielectric injection space.

Alternatively, the present invention is a plasma processing method usinga plasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, a processing vessel configured forcontaining the upper electrode and the lower electrode therein, and afirst high frequency power source connected with the lower electrode andused for generating plasma, wherein the upper electrode and the lowerelectrode are arranged to be opposed to each other, and wherein theplasma processing method comprises the steps of: supplying a dielectricinto a dielectric injection space formed in the upper electrode; placinga substrate on the table; supplying a processing gas into the processingvessel; and changing the processing gas into the plasma between theupper electrode and the lower electrode, so as to perform a plasmaprocess to the substrate with the plasma, wherein the step of supplyingthe dielectric is performed for controlling a supply amount of thedielectric, such that in-plane uniformity of intensity of an electricfield of the plasma can be enhanced, as compared with the case in whichthe dielectric is not supplied into the dielectric injection space.

Alternatively, the present invention is a plasma processing method usinga plasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, a processing vessel configured forcontaining the upper electrode and the lower electrode therein, a firsthigh frequency power source connected with either one of the upperelectrode and the lower electrode and used for generating plasma, and asecond high frequency power source connected with the lower electrodeand used for introducing ions present in the plasma, wherein the upperelectrode and the lower electrode are arranged to be opposed to eachother, and wherein the plasma processing method comprises the steps of:supplying a dielectric into a dielectric injection space formed in theupper electrode; placing a substrate on the table; supplying aprocessing gas into the processing vessel; and changing the processinggas into the plasma between the upper electrode and the lower electrode,so as to provide a plasma process to the substrate with the plasma,wherein the step of supplying the dielectric is performed forcontrolling a supply amount of the dielectric, such that in-planeuniformity of intensity of an electric field of the plasma can beenhanced, as compared with the case in which the dielectric is notsupplied into the dielectric injection space.

Alternatively, the present invention is a plasma processing method usinga plasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, a processing vessel configured forcontaining the upper electrode and the lower electrode therein, and afirst high frequency power source connected with the lower electrode andused for generating plasma, wherein the upper electrode and the lowerelectrode are arranged to be opposed to each other, and wherein theplasma processing method comprises the steps of: supplying a dielectricinto a dielectric injection space formed in the lower electrode; placinga substrate on the table; supplying a processing gas into the processingvessel; and changing the processing gas into the plasma between theupper electrode and the lower electrode, so as to perform a plasmaprocess to the substrate with the plasma, wherein the step of supplyingthe dielectric is performed for controlling a supply amount of thedielectric, such that in-plane uniformity of intensity of an electricfield of the plasma can be enhanced, as compared with the case in whichthe dielectric is not supplied into the dielectric injection space.

Alternatively, the present invention is a plasma processing method usinga plasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, a processing vessel configured forcontaining the upper electrode and the lower electrode therein, a firsthigh frequency power source connected with either one of the upperelectrode and the lower electrode and used for generating plasma, and asecond high frequency power source connected with the lower electrodeand used for introducing ions present in the plasma, wherein the upperelectrode and the lower electrode are arranged to be opposed to eachother, and wherein the plasma processing method comprises the steps of:supplying a dielectric into a dielectric injection space formed in thelower electrode; placing a substrate on the table; supplying aprocessing gas into the processing vessel; and changing the processinggas into the plasma between the upper electrode and the lower electrode,so as to perform a plasma process to the substrate with the plasma,wherein the step of supplying the dielectric is performed forcontrolling a supply amount of the dielectric, such that in-planeuniformity of intensity of an electric field of the plasma can beenhanced, as compared with the case in which the dielectric is notsupplied into the dielectric injection space.

The plasma processing method according to the present invention furthercomprises the steps of: reading data correlating a kind of each processwith an injection amount of the dielectric into the dielectric injectionspace, prior to the step of supplying the dielectric; then controllingthe injection amount of the dielectric into the dielectric injectionspace.

Alternatively, the present invention is a storage medium for storingtherein a computer program for driving a computer to execute a plasmaprocessing method, wherein the plasma processing method uses a plasmaprocessing apparatus including an upper electrode, a table constitutinga lower electrode, a processing vessel configured for containing theupper electrode and the lower electrode therein, and a first highfrequency power source connected with the lower electrode and used forgenerating plasma, wherein the upper electrode and the lower electrodeare arranged to be opposed to each other, and wherein the plasmaprocessing method comprises the steps of: supplying a dielectric into adielectric injection space formed in the upper electrode; placing asubstrate on the table; supplying a processing gas into the processingvessel; and changing the processing gas into the plasma between theupper electrode and the lower electrode, so as to perform a plasmaprocess to the substrate with the plasma, wherein the step of supplyingthe dielectric is performed for controlling a supply amount of thedielectric, such that in-plane uniformity of intensity of an electricfield of the plasma can be enhanced, as compared with the case in whichthe dielectric is not supplied into the dielectric injection space.

Alternatively, the present invention is a storage medium for storingtherein a computer program for driving a computer to execute a plasmaprocessing method, wherein the plasma processing method uses a plasmaprocessing apparatus including an upper electrode, a table constitutinga lower electrode, a processing vessel configured for storing the upperelectrode and the lower electrode therein, a first high frequency powersource connected with either one of the upper electrode and the lowerelectrode and used for generating plasma, and a second high frequencypower source connected with the lower electrode and used for introducingions present in the plasma, wherein the upper electrode and the lowerelectrode are arranged to be opposed to each other, and wherein theplasma processing method comprises the steps of: supplying a dielectricinto a dielectric injection space formed in the upper electrode; placinga substrate on the table; supplying a processing gas into the processingvessel; and changing the processing gas into the plasma between theupper electrode and the lower electrode, so as to perform a plasmaprocess to the substrate with the plasma, wherein the step of supplyingthe dielectric is performed for controlling a supply amount of thedielectric, such that in-plane uniformity of intensity of an electricfield of the plasma can be enhanced, as compared with the case in whichthe dielectric is not supplied into the dielectric injection space.

Alternatively, the present invention is a storage medium for storingtherein a computer program for driving a computer to execute a plasmaprocessing method, wherein the plasma processing method uses a plasmaprocessing apparatus including an upper electrode, a table constitutinga lower electrode, a processing vessel configured for containing theupper electrode and lower electrode therein, and a first high frequencypower source connected with the lower electrode and used for generatingplasma, wherein the upper electrode and the lower electrode are arrangedto be opposed to each other, and wherein the plasma processing methodcomprises the steps of: supplying a dielectric into a dielectricinjection space formed in the lower electrode; placing a substrate onthe table; supplying a processing gas into the processing vessel; andchanging the processing gas into the plasma between the upper electrodeand the lower electrode, so as to perform a plasma process to thesubstrate with the plasma, wherein the step of supplying the dielectricis performed for controlling a supply amount of the dielectric, suchthat in-plane uniformity of intensity of an electric field of the plasmacan be enhanced, as compared with the case in which the dielectric isnot supplied into the dielectric injection space.

Alternatively, the present invention is a storage medium for storingtherein a computer program for driving a computer to execute a plasmaprocessing method, wherein the plasma processing method uses a plasmaprocessing apparatus including an upper electrode, a table constitutinga lower electrode, a processing vessel configured for containing theupper electrode and the lower electrode therein, a first high frequencypower source connected with either one of the upper electrode and thelower electrode and used for generating plasma, and a second highfrequency power source connected with the lower electrode and used forintroducing ions present in the plasma, wherein the upper electrode andthe lower electrode are arranged to be opposed to each other, andwherein the plasma processing method comprises the steps of: supplying adielectric into a dielectric injection space formed in the lowerelectrode; placing a substrate on the table; supplying a processing gasinto the processing vessel; and changing the processing gas into theplasma between the upper electrode and the lower electrode, so as toperform a plasma process to the substrate with the plasma, wherein thestep of supplying the dielectric is performed for controlling a supplyamount of the dielectric, such that in-plane uniformity of intensity ofan electric field of the plasma can be enhanced, as compared with thecase in which the dielectric is not supplied into the dielectricinjection space.

According to the present invention, with the provision of the dielectricinjection space configured for allowing the dielectric to be injectedtherein, to the upper electrode or table constituting the lowerelectrode, each used in the plasma processing apparatus, as well as withthe provision of the dielectric supply passage and dielectric dischargepassage, each being in communication with the dielectric injectionspace, the dielectric can be controllably supplied into the dielectricinjection space. Accordingly, with such control of the amount of thedielectric injected into the dielectric injection space, a capacitorcomponent due to the dielectric injection space can be optionallychanged. Thus, in-plane distribution of the intensity of the electricfield of the plasma can be controlled with ease, thereby to provide theplasma process with significantly higher in-plane uniformity,corresponding to various process conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal side cross section showing one example of anetching apparatus including an upper electrode of the present invention.

FIG. 2 is a longitudinal side cross section showing one example of theupper electrode.

FIG. 3 is a plan view of the upper electrode when it is seen from below.

FIG. 4 is a schematic diagram showing one example of a control unitrelated to the etching apparatus.

FIG. 5 is a schematic diagram showing one exemplary operation of theetching apparatus.

FIG. 6 is a schematic diagram showing another example of the operationof the etching apparatus.

FIG. 7 is a longitudinal side cross section showing another example ofthe upper electrode of the present invention.

FIG. 8 is a longitudinal side cross section showing still anotherexample of the upper electrode of the present invention.

FIG. 9 is a longitudinal side cross section showing one example in whicha recess is provided in a table, rather than provided in the upperelectrode.

FIG. 10 is a longitudinal side cross section showing another example ofthe etching apparatus.

FIGS. 11( a) through 11(e) illustrate profiles, respectively showingresults related to examples of the present invention.

FIGS. 12( a) through 12(f) illustrate other profiles, respectivelyshowing results related to examples of the present invention.

FIGS. 13( a) through 13(e) illustrate other profiles, respectivelyshowing results related to examples of the present invention.

FIGS. 14( a) through 14(d) illustrate other profiles, respectivelyshowing results related to examples of the present invention.

FIGS. 15( a) through 15(d) illustrate other profiles, respectivelyshowing results related to examples of the present invention.

FIG. 16 is a schematic diagram showing a state of plasma in oneconventional etching apparatus.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, one embodiment will be described with reference to FIG. 1,wherein one exemplary upper electrode related to the present inventionis applied to an etching apparatus. FIG. 1 shows one example of theetching apparatus of an RIE (Reactive Ion Etching) type, which isadapted for providing an etching process to a semiconductor wafer(hereinafter referred to as a “wafer”) W having, for example, a 300 mmdiameter. This etching apparatus includes a processing vessel 21 (e.g.,a vacuum chamber having a space hermetically sealed therein) formed ofan electrically conductive material, for example, aluminum; a table 30provided on a central portion of a bottom face of the processing vessel21; and an upper electrode 50 located above the table 30 while beingopposed to the table 30.

An exhaust port 22 is provided through the bottom face of the processingvessel 21, and is communicated with a vacuum exhaust system 23 (orvacuum exhaust means) including a vacuum pump or the like means, via anexhaust pipe 24 provided with a pressure control means (not shown). Atransfer port 25 for the wafer W is provided in a wall face of theprocessing vessel, such that the port 25 can be optically opened andclosed by a gate valve 26. In a site (i.e., an inner wall and a top wallof the processing vessel 21) outside a processing space 1 definedbetween the upper electrode 50 and the table 30 in the processing vessel21, a covering member 21 a is provided for suppressing attachment, tothe apparatus, of unwanted by-products that will be generated, such asby etching. It is noted that the processing vessel 21 is grounded.

The table 30 is composed of a lower electrode 31, which serves as anelectrode member, and a support member 32 adapted for supporting thelower electrode 31 from below. The table 30 is provided on the bottomface of the processing vessel 21, via an insulating member 33. Inaddition, the table 30 is covered, around its side face, by a ringmember 40. Further, a covering member 41 is provided, around the ringmember 40, for suppressing the attachment of the by-products that willbe generated, such as by etching.

To an upper portion of the table 30, an electro-static chuck 34 having aplurality of through-holes (not shown) formed therein is provided. Inthis manner, when some voltage is applied to an electrode film 34 aformed in the electro-static chuck 34 from a high-voltage direct-currentpower source 35, the wafer W will be electro-statically chucked on thetable 30.

In the table 30, a temperature control flow passage 37 is formed. Thistemperature control flow passage 37 is configured for allowing apredetermined temperature control medium to flow therethrough. Thus, thewafer W can be controlled to a desired temperature by the temperaturecontrol medium flowed through the temperature control flow passage 37.Additionally, a gas flow passage 38, configured for supplying a heatconducting gas, such as a He (helium) gas or the like, used as aback-side gas, is provided in the table 30. The gas flow passage 38 isopened at several points in a top face of the table 30. The openings ofthe gas flow passage 38 are respectively communicated with thethrough-holes formed in the electro-static chuck 34. As such, theback-side gas can be supplied to a rear face or back-side face of thewafer W.

To the lower electrode 31, a first high-frequency power source 6 aadapted for supplying first high-frequency power of, for example, 100MHz, and a second high-frequency power source 6 b adapted for supplyingsecond high-frequency power of, for example, 3.2 MHz, which is lowerthan the frequency of the first high-frequency power source 6 a, areconnected, via matching circuits 7 a, 7 b, respectively. The firsthigh-frequency power supplied from the first high-frequency power source6 a is used for changing a processing gas, as will described later, intoplasma, while the second high-frequency power supplied from the secondhigh-frequency power source 6 b is used for applying bias power to thewafer W so as to introduce ions present in the plasma into a surface ofthe wafer.

A focus ring 39 is located on an outer periphery of the lower electrode31, such that the ring 39 surrounds the electro-static chuck 34. Thus,when the plasma is generated, the plasma can be focused on the wafer Wplaced on the table 30, via the focus ring 39.

Between the covering member 41 located in a lower position of theprocessing vessel 21 and the inner wall of the processing vessel 21 (orcovering member 21 a), a baffle plate 28, as a gas distributor forcontrolling the flow of the processing gas, is provided.

Next, one embodiment of the upper electrode 50 of this invention will bedescribed. The upper electrode 50 includes an electrode plate 54, asupport member 51 adapted for supporting the electrode plate 54, and agas diffusion member 54 a located between the electrode plate 54 and thesupport member 51. In this case, the support member 51, gas diffusionmember 54 a and electrode plate 54 are layered in this order from thetop. The support member 51 is provided to have a bottom-face diameter(i.e., a diameter of a bottom face thereof) slightly larger, forexample, by approximately 10 mm, than the diameter of the wafer W, andis formed from electrically conductive aluminum. The upper electrode 50is circumferentially supported by the top wall of the processing vessel21 via an insulating member 52.

As shown in FIG. 2, the gas diffusion member 54 a is formed to have thesame diameter as the bottom-face diameter of the support member 51, andhas a gas supply port 55 provided in a central position of a top facethereof. In the gas diffusion member 54 a, a gas diffusion passage 56,i.e., a horizontally extending space for diffusing a gas, is provided tobe in communication with the gas supply port 55. The gas diffusionmember 54 a is formed from, for example, a metal having higherelectrical resistance, or from a dielectric, such as a PTFE(polytetrafluoroethylene) resin or the like, having a relativepermittivity within a range of from 1 to 10.

The electrode plate 54 is formed from, for example, silicon, and has aplurality of gas discharge ports 53 formed in its bottom face. Each ofthe gas discharge ports 53 is configured for supplying the processinggas into the processing space 1, like a shower, and is in communicationwith the gas diffusion passage 56. The electrode plate 54 is formed tohave the same diameter as the bottom-face diameter of the support member51, and has a thickness t1 of, for example, 5 mm, and resistivity of 0.5Ωm at 25° C.

As shown in FIGS. 2 and 3, a recess 57, having a diameter R of, forexample, 160 mm and a depth t2 of, for example, 5 mm, is formed in acentral portion of the bottom face of the support member 51. The recess57 serves as a dielectric injection space for storing the dielectrictherein, as will be described below, and is located in a positioncorresponding to a central portion of the wafer W. While not shown inFIGS. 1 and 2, a sealing member 58 is provided at the bottom face of thesupport member 51 around the recess 57, wherein the sealing member 58 isfit in a ring-like groove. With such configuration, when the electrodeplate 54 and support member 51 are firmly contacted together, bypressure, due to a fixing means, such as by using bolts or the like (notshown), the recess 57 will be kept in a hermetically sealed state.

Additionally, a gas supply pipe 59 is provided in the central portion ofthe support member 51. The gas supply pipe 59 constitutes a gas flowpassage vertically extending through the support member 51. The gassupply pipe 59 extends, at its lower end portion, through the recess 57,and is airtightly connected with the gas supply port 55 on the top faceof the gas diffusion member 54 a. Accordingly, the recess 57 isairtightly separated from the gas supply pipe 59 and processing space 1.

A top end of the gas supply pipe 59 is connected with a gas supply pipe60 constituting a gas supply passage provided in the top face of thesupport member 51. To an upstream end of the gas supply pipe 60, aprocessing gas supply source 83 storing therein the processing gas usedfor etching is connected, via a gas supply system 100 including a valve81 and a flow-rate controller 82. While not shown in the drawings, aplurality of processing gas supply sources are connected with theprocessing gas supply source 83, via, for example, a plurality of branchpassages, valves and/or flow-rate controllers. As such, suitableprocessing gases can be switched, corresponding to a kind of each waferW that will be subjected to the process.

Furthermore, a dielectric supply passage 61 and a dielectric dischargepassage 62, both connected with a top face (or face opposed to the gasdiffusion member 54 a) of the recess 57, are provided in the supportmember 51, such that the two passages 61, 62 can be in communicationwith the recess 57, respectively. The dielectric supply passage 61 isopened at a level of the top face of the recess 57, while the dielectricdischarge passage 62 is opened in the recess 57, in a position adjacentto the gas diffusion member 54 a. To an upstream end of the dielectricsupply passage 61, a dielectric supply source 65 is connected, via avalve 63 and a liquid feeding means 64, such as a rotary pump or thelike. In the dielectric supply source 65, a dielectric is stored, whichis a liquid having a relative permittivity of approximately 1.9, such asa fluorine-containing inert liquid (C₆F₁₄). The dielectric supplypassage 61 is also opened in the dielectric supply source 65 in aposition adjacent to a bottom face thereof.

To a portion of the dielectric supply passage 61 extending downstream(or on the side of the support member 51) relative to the valve 63, oneend of a discharge gas supply passage 91 is connected. The discharge gassupply passage 91 is configured for supplying, for example, a nitrogengas, into the recess 57, via the dielectric supply passage 61, so as todischarge the dielectric stored in the recess 57 to the outside, via thedielectric discharge passage 62, by pressure of the nitrogen gas.Meanwhile, the other end of the discharge gas supply passage 91 isconnected with a discharge gas supply source 94 storing, for example,the nitrogen gas, therein, via a valve 92 and a flow-rate controller 93.To a downstream end (or one end opposite to the recess 57) of thedielectric discharge passage 62, the dielectric supply source 65 isconnected. Thus, the dielectric stored in the recess 57 can be returnedinto the dielectric supply source 65, via the dielectric dischargepassage 62. To a top face of the dielectric supply source 65, a gasexhaust pipe 66, configured for discharging a gas present in thedielectric supply source 65 to the outside, is connected. When thedielectric and/or nitrogen gas is supplied into the recess 57, thenitrogen gas that has been supplied into the dielectric supply source 65via the dielectric discharge passage 62 is discharged, by opening thevalve 67 provided to the gas exhaust pipe 66. These valves 63, 67, 92,liquid feeding means 64 and flow-rate controller 93 constitute,together, a dielectric supply system 101.

Above the recess 57 in the support member 51, a temperature control flowpassage 71, which serves as a temperature control mechanism, having asnake-like shape, extends in a horizontal direction, as shown in FIG. 3.To both ends of the temperature control flow passage 71, atemperature-control-medium supply passage 72 and atemperature-control-medium discharge passage 73, both extending throughthe top face of the support member 51, are connected, respectively. Toan upstream end of the temperature-control-medium supply passage 72, asshown in FIG. 1, a temperature-control-medium supply source 78 isconnected, via a temperature control mechanism 75, such as a heater, achiller and the like, a valve 76, and a liquid feeding means 77including a flow rate controller. Thus, the temperature of the electrodeplate 54 can be controlled within a predetermined range of, for example,60° C. to 200° C., with a temperature control medium controlled withinsuch a predetermined temperature range of, for example, 60° C. to 200°C. and flowed through the support member 51. Thetemperature-control-medium supply source 78 is also connected with adownstream end (or discharge side end) of the temperature-control-mediumdischarge passage 73. Thus, the temperature control medium can becirculated by the liquid feeding means 77. In this case, the temperaturecontrol mechanism 75, valve 76 and liquid feeding means 77 constitute,together, a temperature-control-medium supply system 102.

Additionally, in the top face of the support member 51, a heater 51 aconnected with a power source 110 is provided as a part of thetemperature control mechanism. The heater 51 a is adapted for heatingthe electrode plate 54 up to, for example, 60° C. to 200° C., via thesupport member 51 and gas diffusion member 54 a. On a top face of theinsulating member 52 beside the heater 51 a, a temperature detectionmeans 51 b, such as a thermocouple or the like, is provided. Thus, thetemperature of the central portion of the bottom face of the electrodeplate 54 can be measured, indirectly, based on a temperature detected onthe top face of the insulating member 52. With such detection of thetemperature of the electrode plate 54 by the temperature detection means51 b, a control unit 10, as will be described later, can control thetemperature of the electrode plate 54, by controlling the temperature ofthe heater 51 a as well as by controlling the temperature and flow rateof the temperature control medium flowed through the temperature controlflow passage 71. It is noted that the support member 51 is grounded, andthat FIG. 3 shows the support member 51 when it is seen from below.

This etching apparatus includes, as shown in FIG. 4, the control unit 10composed of, for example, a computer, as a means for controlling aninjection amount of the dielectric after reading the injection amount.The control unit 10 includes a data processing unit or the like, whichis composed of a CPU 11, a memory 12, a program 13 and a work memory 14for the working. The memory 12 has storage regions respectively providedfor a kind of each process (recipe). Namely, in each of the storageregions of the memory 12, values of the processing conditions for eachprocess, including a kind of each processing gas, a processing pressure,a processing temperature, a processing time, a gas flow rate, afrequency and power of the high frequency power and the like; and data,such as the amount (volume) of the dielectric supplied into the recess57, temperature of the electrode plate 54 and the like, are written,respectively. In this case, the amount (volume) of the dielectric andthe temperature of the electrode plate 54 have been obtained, inadvance, for example, by experiments and/or calculations, such that thein-plane uniformity of the electric field of the plasma (or electrondensity) can be adequately applicable to a selected process, uponchanging the processing gas into the plasma under the above processingconditions, and such that a capacitor component due to the recess 57 andresistance (or resistivity) of the electrode plate 54 can be set atpredetermined values, respectively. More specifically, the amount of thedielectric in the recess 57 and the temperature of the electrode plate54, for rendering the in-plane uniformity of the electric field of theplasma applicable or preferable, can be obtained for the followingreasons.

Assuming that electrical capacitance of the capacitor component providedby the recess 57, the relative permittivity of the dielectricconstituting the capacitor, an area of the electrode also constitutingthe capacitor and a thickness of the dielectric constituting thecapacitor are expressed by C, ∈, S, d, respectively, the followingrelation can be obtained.

C=∈(S/d)  (1)

In this relational expression (1), the thickness d can be controlled, bycontrolling the amount of the dielectric supplied into the recess 57. Asa result, the capacitance C of the capacitor component due to the recess57 can be changed.

For instance, when the capacitance C of the capacitor component due tothe recess 57 is decreased, impedance between the upper electrode 50 andthe table 30 will be increased. Thus, apparent high frequency powersupplied into the processing space 1 will be decreased, as such reducingthe intensity of the electric field of the plasma. Contrary, when thecapacitance C of the capacitor component due to the recess 57 isincreased, the impedance between the upper electrode 50 and the table 30will be decreased. Thus, the intensity of the electric field of theplasma will be increased. Therefore, by controlling the capacitance C ofthe capacitor component due to the recess 57, corresponding to thein-plane distribution of the electric field of the plasma, or byreducing the capacitance C of the capacitor component by injecting thedielectric into the recess 57, in a region of higher intensity of theelectric field of the plasma (or central region of the wafer W), thein-plane uniformity of the plasma can be positively enhanced.

Further, assuming that a skin depth of the electrode plate 54 relativeto the high frequency power supplied from the first high-frequency powersource 6 a, the frequency of the high frequency power supplied from thefirst high-frequency power source 6 a, magnetic permeability of theelectrode plate 54, resistivity of the electrode plate 54 and the ratioof the circumference of a circle to its diameter are expressed by δ, f,μ, ρ, π, respectively, the following relation can be established.

δ=(2/ωμσ)^(1/2), ω=2πf, σ=1/ρ  (2)

Therefore, by controlling the temperature of the electrode plate 54, thevalue ρ in this relation (2) can be controlled. Thus, with such controlof the temperature of the electrode plate 54, an effect of the plasmadue to the recess 57 can be changed, thereby controlling thedistribution of the electric field.

Namely, this embodiment is intended to control the amount of thedielectric supplied into the recess 57 as well as the temperature of theelectrode plate 54. It should be appreciated that each processingparameter may be calculated each time a selected process is performed,without storing the amount of the dielectric supplied into the recess 57and temperature of the electrode plate 54, in advance, in the memory 12.

The program 13 incorporates instructions, each provided for sending acontrol signal to each part or unit of the etching apparatus from thecontrol unit 10, so as to drive the part or unit to carry out each stepas will be described later, thereby performing a necessary process ortransfer operation for the wafer W. Additionally, the program 13incorporates other instructions, respectively provided for controllingthe liquid feeding means 64, 77, valves 63, 67, 92 and flow-ratecontroller 93, so as to achieve the amount of the dielectric andtemperature of the electrode plate 54 written in the above memory 12.When each instruction of the program 13 is executed by the CPU 11, theprocessing conditions are read by the work memory 14, and the controlsignal (or signals) corresponding to the conditions is then sent to eachpart or unit of the etching apparatus. The program 13 (including aprogram related to input and/or display operations of the processingconditions) is first stored in a storage unit 15, i.e., a computerstorage medium, such as a flexible disk, a compact disk, an MO (ormagneto-optical disk) or the like, and is then installed into thecontrol unit 10.

Next, an operation of the etching apparatus will be, described, withreference to FIGS. 5 and 6. First, a recipe of the process that is aboutto be performed is selected, and the process conditions corresponding tothe selected recipe are then read by the work memory 14 from the memory12. Thereafter, as shown in FIG. 5, the valves 63, 67 are opened, whilethe liquid feeding means 64 is actuated to supply the dielectric intothe recess 57 from the dielectric supply source 65, such that the amountof the dielectric in the recess 57 will correspond to the processingconditions. As the dielectric is filled in the recess 57, an ambientgas, for example, a nitrogen gas, filled in advance in the recess 57, ispurged by the dielectric toward the dielectric supply source 65 via thedielectric discharge passage 62. Eventually, the nitrogen gas isdischarged to the outside of the etching apparatus via the gas exhaustpassage 66. Simultaneously, the temperature control medium is flowedthrough the temperature control flow passage 71 by the liquid feedingmeans 77, while the heater 51 a is turned on. Thus, the temperature ofthe electrode plate 54 can be controlled at a predetermined temperature,for example, 90° C.

Then, the gate valve 26 is opened, and the wafer W is carried into theprocessing vessel 21 by a carrier means (not shown), and placed on thetable 30. On the surface of the wafer W, for example, a silicon oxidefilm (not shown) is formed. In addition, a patterned resist mask (notshown) is layered on the silicon oxide film. Thereafter, the wafer W ischucked by the electro-static chuck 34, while the flow rates of thetemperature control medium and heat conducting gas, respectively flowedthrough the temperature control flow passage 37 and gas flow passage 38,are controlled, respectively, to adjust the temperature of the wafer Wat, for example, 30° C. Subsequently, the processing gas, for example,C₄F₈/A_(r)/O₂, of a predetermined flow rate is supplied into theprocessing vessel 21, while the throughput of the vacuum exhaust system23 is controlled to set the interior of the processing vessel 21 at adesired degree of vacuum.

Thereafter, predetermined high frequency power is supplied to the table30 from the first high-frequency power source 6 a and secondhigh-frequency power source 6 b, respectively, so as to change theprocessing gas into the plasma as well as to introduce the ions presentin the plasma into the wafer W. At this time, if the recess 57 (ordielectric) is not provided in the upper electrode 50, the etchingprocess would be progressed at a higher speed around the central portionof the wafer W, as shown in FIG. 16, while the etching rate would besignificantly lowered around the periphery of the wafer W, as comparedwith the central portion. However, by using the upper electrode 50 ofthis embodiment, the amount of the dielectric in the recess 57 and thetemperature of the electrode plate 54 can be optionally controlled asdescribed above. Therefore, the intensity of the electric field (orelectron density) around the central portion of the wafer W can beadequately decreased. Thus, as shown in FIG. 6, the intensity of theelectric field of the plasma can be substantially uniformed in thesurface of the wafer W, thereby rendering the etching rate adequatelyuniform in the surface. It is noted that arrows depicted in the plasmashown in FIG. 6 schematically express the intensity of the electricfield of the plasma, respectively.

Once the etching process is completed, the supply of the high frequencypower is stopped, and the supply of the processing gas is also stopped.Thereafter, the processing vessel 21 is evacuated, and the wafer W isthen carried out from the processing vessel 21. Then, in the case offurther providing a desired process to another wafer W that will beprocessed under different conditions, the amount of the dielectric inthe recess 57 and the temperature of the electrode plate 54 are newlycontrolled, corresponding to a new recipe, via the dielectric supplysystem 101 and temperature-control-medium supply system 102, in the samemanner as described above. In this case, if the amount of the dielectricin the recess 57 is required to be increased, the valves 63, 67 arerespectively opened, so that the dielectric can be further supplied intothe recess 57 by the liquid feeding means 64. Contrary, if the amount ofthe dielectric in the recess 57 is needed to be decreased, the valve 63is closed while the valves 67, 92 are respectively opened, so that thenitrogen gas can be supplied into the recess 57 from the discharge gassupply source 94. Consequently, the dielectric in the recess 57 can bedischarged toward the discharge supply source 65 via the dielectricdischarge passage 62.

According to this embodiment, by providing the recess 57 in the supportmember 51 as well as the provision of the dielectric supply passage 61and dielectric discharge passage 62 both communicated with the recess57, the dielectric can be controllably supplied into the recess 57.Additionally, the in-plane distribution of the intensity of the electricfield of the plasma that will be changed, corresponding to the processconditions, such as the kind of each wafer W (e.g., the composition ofthe film to be etched and/or mask), kind of each processing gas and/orgas pressure, is obtained in advance, by experiments and/orcalculations. Therefore the amount of the dielectric in the recess 57can be optionally controlled to render the in-plane distribution of theintensity of the electric field of the plasma substantially uniformed.Thus, the in-plane distribution of the intensity of the electric fieldof the plasma generated from the processing gas can be uniformed withease, as such providing the etching process with higher in-planeuniformity, corresponding to various processing conditions. Moreover, inaddition to the control of the amount of the dielectric in the recess57, the resistance (or resistivity) of the electrode plate 54 can beadequately controlled, by controlling the temperature of the electrodeplate 54. Therefore, as is also demonstrated in several examplesdiscussed below, the in-plane distribution of the intensity of theelectric field of the plasma can be finely controlled.

Because the electrode plate 54 (and/or gas diffusion member 54 a) isprovided to cover the bottom face of the support member 51, the recess57 formed in the support member 51, including a face joined to theelectrode plate 54, is not exposed to the processing space 1. Thus,occurrence of unwanted particles from each face of the recess 57 can besuppressed or substantially eliminated.

In the above example, the diameter R of the recess 57 is 160 mm, and thedepth t2 thereof is 5 mm. However, as seen in the examples discussedbelow, the diameter R may be changed within a range of approximately 100to 300 mm, while the thickness t2 may be set within a range ofapproximately 5 to 10 mm. Additionally, in the above example, the amountof the dielectric in the recess 57 and the temperature of the electrodeplate 54 are controlled or changed together. However, only the amount ofthe dielectric supplied into the recess 57 may be controlled, withoutany control of the temperature of the electrode plate 54. As thematerial for the electrode plate 54, for example, carbon or the likematerial other than silicon can be used.

In the above example, the gas diffusion passage 56 configured fordiffusing the processing gas into the gas diffusion member 54 a isprovided. However, the electrode plate 54 may be modified as shown inFIG. 7. Furthermore, as shown in FIG. 8, the gas diffusion member 54 amay be eliminated. Instead, the electrode plate 54 may be directlycontacted with the support member 51. In this case, a gas introductionpassage 121, extending through the electrode plate 54 while being incommunication with the gas supply pipe 59, may be provided in theelectrode plate 54. Additionally, as shown in FIG. 8, a gas supplymember 122 a, having a downwardly convex dome-like shape and a pluralityof apertures formed therein, may be provided on the bottom face of theelectrode plate 54, such that the gas supply member 122 a can be incommunication with the gas introduction passage 121. In this manner, theprocessing gas can be radially supplied onto the wafer W from the gasinjection ports 122 of the dome-like gas supply member 122 a. With suchconfiguration, a similar effect to the above example can also beobtained. It is noted that the recess 57 may be completely surrounded bythe support member 51.

Unlike the table 30 in which the electro-static chuck 34, temperaturecontrol flow passage 37 or gas flow passage 38 are provided as describedabove, the recess 57 is provided in the support member 51, with pipesand wirings arranged in significantly reduced numbers, as compared withthe table 30. Therefore, such a recess 57 can be formed easily. However,as shown in FIG. 9, the recess 57 may be provided in the table 30 (orlower electrode 31). In such a case, the lower electrode 31 serves as adielectric-injection-space-constituting member. In FIG. 9, the recess 57is located more adjacent the wafer W than that in the above example.Therefore, the intensity of the electric field of the plasma can befurther uniformed due to the dielectric, thereby to provide the etchingprocess with much higher in-plane uniformity. In this case, thethickness of the electrode of the electro-static chuck 34 is set at, forexample, 20 mm or less. Additionally, in FIG. 9, the same partsdescribed in the above example are designated by the same referencenumerals. Furthermore, the recess 57 may be provided in both of thesupport member 51 and table 30. While the processing gas is suppliedonto the wafer W from the upper electrode 50 in the above example, thesupply manner of the processing gas is not limited to this manner. Forinstance, the gas supply pipe 60 may be provided laterally to the waferW.

In the above example, the fluorine-containing inert liquid having arelative permittivity of 1.9 is used as the dielectric supplied into therecess 57. However, other CF-type polymers or CHF-type polymers (e.g.,CFC-type liquids nonvolatile at a normal temperature) having a relativepermittivity within a range of approximately 1 to 3 may also be used.Alternatively, as the dielectric, powder formed from ceramics, e.g.,Al₂O₃, having a relative permittivity of approximately 1 to 20, S_(i)O₂(or glass wool) having a relative permittivity of approximately 1 to 4(or 1 to 7), powder of a resin, e.g., PTFE, having a relativepermittivity of approximately 2, and a nitrogen (N₂) gas having arelative permittivity of approximately 1 may be used. Alternatively, theinterior of the recess 57 may be brought into a vacuum state (∈: 1), bysuitably providing a valve, a flow-rate controller and a vacuum pump(not shown) to the dielectric discharge passage 62. Additionally, theabove dielectrics may be used in a mixed state.

Alternatively or additionally, several storage tanks may be provided forstoring therein each of such dielectrics as mentioned above, so that thekind of each dielectric supplied into the recess 57 can be changed,corresponding to the various processing conditions. In this case, thevalue ∈ in the above relation can also be controlled. Thus, thedistribution of the intensity of the electric field can be controlled ina greater range than in the above example. Furthermore, in the aboveexample, the dielectric can be circulated between the recess 57 and thedielectric supply source 65 via the dielectric discharge passage 62.However, in the case of using the aforementioned gas as the dielectric,such a gas may be discharged to the outside via the dielectric dischargepassage 62, without being circulated in the system.

In the above example, the amount of the dielectric injected into therecess 57 is controlled for each recipe. However, for example, in such acase in which the in-plane distribution of the intensity of the electricfield of the plasma is changed during a certain process provided to thewafer W, the amount of the dielectric may be controlled during theprocess, in response to the change.

As described above, one method for controlling the relative permittivityof the upper electrode 50 has been discussed, with respect to the casein which the intensity of the electric field of the plasma around thecentral region of the wafer W is relatively increased, by way ofexample. This invention can also be applied to the case in which theintensity of the electric field of the plasma in the central region ofthe wafer W is relatively lowered. In such a case, the dielectric havinga relatively high relative permittivity may be supplied into the recess57, or otherwise the temperature of the electrode plate 54 may belowered. Alternatively, as described above, both of the amount of thedielectric in the recess 57 and the temperature of the electrode plate54 may be controlled at the same time.

Other than such a lower-electrode-two-high-frequency-type apparatus asdescribed above, the present invention can also be applied to anupper-and-lower-electrode-two-high-frequency-type etching apparatus, asshown in FIG. 10. Also in this case, the intensity of the electric fieldof the plasma in the surface of the wafer W can be uniformed, thusproviding the etching process with significantly higher in-planeuniformity. Although not shown in FIG. 10, the support member 51 isgrounded via a low pass filter (LPF), while the lower electrode 31 isgrounded via a high pass filter (HPF). Furthermore, in a structure asshown in FIG. 1, a lower-electrode-one-high-frequency-type apparatus,which is not provided with the second high-frequency power source 6 bfor introducing the ions present in the plasma, is also applicableherein.

Other than the etching process, this invention may also be applied toanother plasma processing apparatus configured for performing the ashingprocess, CVD process or the like, with the plasma.

Furthermore, the region in which the recess 57 is provided is notlimited to the region corresponding to the central portion of the waferW. For instance, the recess 57 may be provided to have a ring-likeshape, in a position corresponding to the periphery of the wafer W,along the circumference of the upper electrode 50. As the upperelectrode 50 in this case, one construction can be mentioned, by way ofexample. Namely, in this construction, a first dielectric having arelative permittivity of, for example, ∈1, is embedded in the positioncorresponding to the central portion of the wafer W, with a seconddielectric of a relative permittivity lower than ∈1 being injected intothe recess 57, while surrounding the first dielectric.

EXAMPLES

In order to study influence on the plasma, due to the amount of thedielectric of the upper electrode 50 and the temperature of theelectrode plate 54 in the present invention, the magnitude of a sheathelectric field (or voltage) was calculated, over a region from thecentral position to the periphery of the wafer W, in a position spacedaway from and along the bottom face of the electrode plate 54 (i.e., 3mm lower than the bottom face of the electrode plate 54), by simulationusing Multiphysics (softwear produced by Ansis Co., Ltd.), with therelative permittivity of the upper electrode 50 being variously changed,as will be described below. It should be appreciated that the sheathelectric field was used as an index for assessing the intensity of theelectric field of the plasma because the sheath electric field isdirectly influenced by a state or condition (i.e., distribution of theintensity of the electric field) of the plasma. In FIGS. 11 through 15,a ratio obtained by dividing each magnitude of the calculated sheathelectric field by a maximum value thereof in the surface of the wafer Wis shown, respectively. For the simulation, the calculation wasperformed, on the assumption that the resistivity of the plasma was 1.5Ωm.

Example 1

Under the following conditions, the simulation as described above wasperformed. In this simulation, the magnitude of the sheath electricfield was calculated, with the size of the recess 57 being fixed, whilethe relative permittivity of the dielectric in the recess 57 and theresistivity of the electrode plate 54 were changed, respectively.

(Simulation Conditions)

Diameter R of the recess 57: 100 mm

Thickness t2 of the recess 57: 5 mm

High frequency for the plasma generation: 100 MHz

Relative permittivity (∈) of the dielectric in the recess 57:1/3.8/10/50

Resistivity (Ωm) of the electrode plate 54: no/0.02/0.5/1/5/10

As the material actually used for setting the dielectric in the recess57 at the relative permittivity as described above, a vacuum (∈: 1),powder of silicon dioxide (∈: 3.8), powder of ceramics, e.g., Al₂O₃ (∈:10 to 50) and the like can be mentioned. In the case of setting theresistivity into the range as described above, each desired range of theresistivity can be achieved, by controlling the temperature of theelectrode plate 54 as well as by controlling a doping amount of suitableimpurities, such as boron (B) and the like, by properly doping them intothe electrode plate 54.

(Simulation Results)

FIG. 11( a) shows a result obtained by calculating the sheath electricfield, without the electrode plate 54, while changing the relativepermittivity of the dielectric in the recess 57, and FIGS. 11( b)through 11(e) show results obtained by calculating the sheath electricfield, while changing the relative permittivity of the dielectric in therecess 57, as described above, as well as changing the resistivity ofthe electrode plate 54, respectively. In FIGS. 11( b) through 11(e), avalue shown in FIG. 11( a), which was calculated without the electrodeplate 54, is also shown, as a reference. It is noted that each legendshown in FIGS. 11( b) through 11(e) designates the resistivity of theelectrode plate 54.

With this simulation, it was found that the intensity of the electricfield of the plasma over a region corresponding to the recess 57 (i.e.,a region from the center of the wafer W to an approximately 50 mm radialpoint) can be reduced by gradually decreasing the relative permittivityof the recess 57. Such reduction of the intensity of the electric fieldof the plasma can be attributed to the fact that the high frequencypower for generating the plasma, supplied into the processing space 1,is locally decreased in the region corresponding to the recess 57. Inaddition, it was found that the intensity of the electric field of theplasma can be controlled, over the whole surface of the wafer W, bychanging the resistivity of the electrode plate 54 together with therelative permittivity of the recess 57. Specifically, with decrease ofthe resistivity of the electrode plate 54, a gradient of the change inthe intensity of the electric field of the plasma at a pointcorresponding to an outer periphery of the recess 57 (i.e., the 50 mmradial point from the center of the wafer W) becomes more gentle.

Therefore, even in the case in which the intensity of the electric fieldof the plasma is considerably increased in the central portion of thewafer W as described above, the magnitude of the sheath electric field(or intensity of the electric field of the plasma) can be controlled,corresponding to each state or condition of the plasma (i.e., theprocessing conditions or the like), in order to enhance the in-planeuniformity, by controlling the amount of the dielectric supplied intothe recess 57 and the temperature of the electrode plate 54. Thus, thewafer W can be etched with higher in-plane uniformity.

Example 2

Another simulation similar to the simulation in the above Example 1 wascarried out, with the recess 57 having a 200 mm diameter R. As shown inFIGS. 12( a) to 12(e), it was found that the intensity of the electricfield of the plasma can be reduced, over the region corresponding to therecess 57 (i.e., a region from the center of the wafer W to anapproximately 100 mm radial point) can be reduced by graduallydecreasing the relative permittivity of the recess 57, in the samemanner as in the above simulation. Similarly, it was found that theintensity of the electric field of the plasma can be controlled, overthe whole surface of the wafer W, by changing the resistivity of theelectrode plate 54 together with the relative permittivity of the recess57.

Additionally, as shown in FIG. 12( f), the intensity of the electricfield of the plasma can be similarly controlled, by changing therelative permittivity of the dielectric in the recess 57 as well as bychanging the thickness t2 of the recess 57, from 5 mm to 1.31 mm or 0.5mm.

Example 3

Next, as shown in FIG. 13, still another simulation similar to thesimulation in the above Example 1 was carried out, with the recess 57having a 300 mm diameter R. Also in this simulation, it was found thatthe intensity of the electric field of the plasma can be reduced, overthe region corresponding to the recess 57 (i.e., a region from thecenter of the wafer W to an approximately 150 mm radial point) can bereduced by gradually decreasing the relative permittivity of the recess57, in the same manner as described above. Again, it was found that theintensity of the electric field of the plasma can be controlled, overthe whole surface of the wafer W, by changing the resistivity of theelectrode plate 54 together with the relative permittivity of the recess57. From these results, it was found that the diameter R of the recess57 is preferably set at a value less than the diameter of the supportmember 51, for example, 300 mm or less, because the sheath electricfield (or intensity of the electric field of the plasma) is changed,using each end (or peripheral end) of the dielectric in the recess 57 asa node (or fixed end).

Example 4

Next, in the above Example 3, another simulation for calculating themagnitude of the sheath electric field was carried out, with thethickness t2 of the recess 57 being set at 10 mm, while the relativepermittivity of the dielectric in the recess 57 and the resistivity ofthe electrode plate 54 were respectively changed.

As a result, as shown in FIG. 14, it was found that the magnitude of thesheath electric field can be further reduced than the result of theabove Example 3 (t2: 5 mm), by setting the thickness t2 of the recess 57at 10 mm. Thus, it was found that the intensity of the electric field ofthe plasma can be controlled in a greater range by increasing thethickness t2 of the recess 57.

Example 5

In this example, still another simulation was carried out, with the sizeof the recess 57 and the relative permittivity of the dielectric in therecess 57 being respectively fixed, while the resistivity of theelectrode plate 54 and the frequency of the high frequency power usedfor the plasma generation were respectively changed.

(Simulation Conditions)

Diameter R of the recess 57: 300 mm

Thickness t2 of the recess 57: 5 mm

Relative permittivity (∈) of the dielectric in the recess 57: 1

High frequency for the plasma generation: 2/13.6/40/100/200 MHz

Resistivity (Ωm) of the electrode plate 54: 0.5/1/5/10

(Simulation Results)

As a result, as shown in FIG. 15, it was found that the sheath electricfield will be changed into a greater wave form, with increase of thefrequency of the high frequency power. In addition, it was found thatthe degree of this change will be higher, with increase of theresistivity of the electrode plate 54.

From the results of the above Experiments 1 through 5, it was found thatthe distribution of the sheath electric field can be variously changed,by suitably changing the diameter R, thickness t2 and relativepermittivity of the recess 57 (or amount and/or kind of each dielectricsupplied into the recess 57) as well as by changing the resistivity ofthe electrode plate 54. Accordingly, it was found that the in-planeuniformity of the intensity of the electric field of the plasma can besubstantially enhanced, by controlling the amount and/or kind of eachdielectric supplied into the recess 57, dimensions of the recess 57,temperature of the electrode plate 54 and the like, in order to reduceor eliminate unwanted change of the intensity of the electric field ofthe plasma, even in the case in which the in-plane uniformity of theelectron density of the plasma may tend to be considerably deterioratedby changing the frequency of the high frequency power and/or otherprocessing parameters. This can be achieved, by carrying out theexperiments and/or simulations as described above, in advance, in orderto check or estimate how the intensity of the electric field will bechanged. It is noted that each legend shown in FIG. 15 denotes thefrequency of the high frequency power.

1. An electrode for use in a plasma process, wherein the electrode isprovided to be opposed to a lower electrode on which a substrate isplaced in a processing space, wherein high frequency power is suppliedto a space between the electrode and the lower electrode, so as togenerate plasma therein and perform the plasma process to the substrate,and wherein the electrode comprises: an electrode plate provided to beopposed to the lower electrode; a support member provided opposite tothe lower electrode across the electrode plate, configured forsupporting the electrode plate, and having a dielectric injection spaceformed therein such that a dielectric used for controlling intensity ofan electric field in the processing space can be injected into thedielectric injection space; a dielectric supply source connected withthe dielectric injection space of the support member via a dielectricsupply passage and configured for supplying the dielectric into thedielectric injection space; and a dielectric discharge passage connectedwith the dielectric injection space of the support member and configuredfor discharging the dielectric from the dielectric injection space. 2.The electrode for use in the plasma process according to claim 1,wherein the dielectric injection space of the support member is providedalong a face on the side of the electrode plate of the support member.3. The electrode for use in the plasma process according to claim 1,wherein a member having a gas diffusion space formed therein isprovided, the gas diffusion space being connected with a processing gassupply source configured for supplying a processing gas to thesubstrate, and wherein a plurality of gas discharge ports are providedon the electrode plate, each of the gas discharge ports being incommunication with the gas diffusion space and configured for injectingthe processing gas into the processing space, like a shower.
 4. Theelectrode for use in the plasma process according to claim 3, whereinthe member having the gas diffusion space formed therein is also used asthe electrode plate or used as the support member.
 5. The electrode foruse in the plasma process according to claim 3, wherein the memberhaving the gas diffusion space formed therein is provided between theelectrode plate and the support member.
 6. The electrode for use in theplasma process according to claim 5, wherein the member having the gasdiffusion space formed therein is formed from a dielectric having arelative permittivity within a range of 1 to
 10. 7. The electrode foruse in the plasma process according to claim 1, wherein a gas supplymember is provided to be projected downward from a central portion ofthe electrode plate, the gas supply member having a dome-like shape anda plurality of gas discharge apertures formed therein, each of the gasdischarge apertures being configured for injecting the processing gasinto the processing space.
 8. The electrode for use in the plasmaprocess according to claim 1, wherein a temperature control mechanismadapted for controlling the temperature of the support member isprovided to the support member.
 9. An electrode for use in a plasmaprocess, wherein the electrode is provided to be opposed to an upperelectrode in a processing space, wherein high frequency power issupplied to a space between the electrode and the upper electrode, so asto generate plasma therein and perform the plasma process to a substrateplaced on one face of the electrode, and wherein the electrodecomprises: an electrode member provided to be opposed to the upperelectrode, wherein at least one of a first high frequency power sourcefor generating the plasma and a second high frequency power source forintroducing ions present in the plasma is connected with the electrodemember; a dielectric-injection-space-constituting member having adielectric injection space formed therein such that a dielectric usedfor controlling intensity of an electric field in the processing spacecan be injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of thedielectric-injection-space-constituting member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space and configured for discharging the dielectricfrom the dielectric injection space.
 10. The electrode for use in theplasma process according to claim 1 or 9, wherein the dielectricinjection space is provided in a position corresponding to a centralportion of the substrate.
 11. The electrode for use in the plasmaprocess according to claim 1 or 9, wherein the dielectric dischargepassage is connected with the dielectric supply source, such that thedielectric can be circulated between the dielectric injection space andthe dielectric supply source.
 12. The electrode for use in the plasmaprocess according to claim 1 or 9, further comprising a storage unitadapted for storing therein data correlating a kind of each process withan injection amount of the dielectric into the dielectric injectionspace, and a means adapted for reading the injection amount of thedielectric corresponding to the kind of each selected process from thestorage unit then controlling the injection amount of the dielectric.13. A plasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, and a processing vessel having aprocessing space containing the upper electrode and the lower electrodetherein, the plasma processing apparatus comprising: a first highfrequency power source connected with the lower electrode and used forgenerating plasma; a gas supply passage configured for supplying aprocessing gas into the processing vessel; and a vacuum exhaust meansadapted for evacuating the interior of the processing vessel, whereinthe upper electrode comprises: an electrode plate provided to be opposedto the lower electrode; a support member provided opposite to the lowerelectrode across the electrode plate, configured for supporting theelectrode plate, and having a dielectric injection space formed thereinsuch that a dielectric used for controlling intensity of an electricfield in the processing space can be injected into the dielectricinjection space; a dielectric supply source connected with thedielectric injection space of the support member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space of the support member and configured fordischarging the dielectric from the dielectric injection space.
 14. Aplasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, and a processing vessel having aprocessing space containing the upper electrode and lower electrodetherein, the plasma processing apparatus comprising: a first highfrequency power source connected with the lower electrode and used forgenerating plasma; a gas supply passage configured for supplying aprocessing gas into the processing vessel; and a vacuum exhaust meansadapted for evacuating the interior of the processing vessel, whereinthe lower electrode comprises: an electrode member provided to beopposed to the upper electrode; adielectric-injection-space-constituting member having a dielectricinjection space formed therein such that a dielectric used forcontrolling intensity of an electric field in the processing space canbe injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of thedielectric-injection-space-constituting member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space and configured for discharging the dielectricfrom the dielectric injection space.
 15. A plasma processing apparatusincluding an upper electrode, a table constituting a lower electrode,and a processing vessel having a processing space containing the upperelectrode and the lower electrode therein, the plasma processingapparatus comprising: a first high frequency power source connected witheither one of the upper electrode and lower electrode and used forgenerating plasma; a second high frequency power source connected withthe lower electrode and used for introducing ions present in the plasma;a gas supply passage configured for supplying a processing gas into theprocessing vessel; and a vacuum exhaust means adapted for evacuating theinterior of the processing vessel into a vacuum state, wherein the upperelectrode comprises: an electrode plate provided to be opposed to thelower electrode; a support member provided opposite to the lowerelectrode across the electrode plate, configured for supporting theelectrode plate, and having a dielectric injection space formed thereinsuch that a dielectric used for controlling intensity of an electricfield in the processing space can be injected into the dielectricinjection space; a dielectric supply source connected with thedielectric injection space of the support member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space of the support member and configured fordischarging the dielectric from the dielectric injection space.
 16. Aplasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, and a processing vessel having aprocessing space containing the upper electrode and the lower electrodetherein, the plasma processing apparatus comprising: a first highfrequency power source connected with either one of the upper electrodeand the lower electrode and used for generating plasma; a second highfrequency power source connected with the lower electrode and used forintroducing ions present in the plasma; a gas supply passage configuredfor supplying a processing gas into the processing vessel; and a vacuumexhaust means adapted for evacuating the interior of the processingvessel, wherein the lower electrode comprises: an electrode memberprovided to be opposed to the upper electrode; adielectric-injection-space-constituting member having a dielectricinjection space formed therein such that a dielectric used forcontrolling intensity of an electric field in the processing space canbe injected into the dielectric injection space; a dielectric supplysource connected with the dielectric injection space of thedielectric-injection-space-constituting member via a dielectric supplypassage and configured for supplying the dielectric into the dielectricinjection space; and a dielectric discharge passage connected with thedielectric injection space and configured for discharging the dielectricfrom the dielectric injection space.
 17. A plasma processing methodusing a plasma processing apparatus including an upper electrode, atable constituting a lower electrode, a processing vessel configured forcontaining the upper electrode and the lower electrode therein, and afirst high frequency power source connected with the lower electrode andused for generating plasma, wherein the upper electrode and the lowerelectrode are arranged to be opposed to each other, and wherein theplasma processing method comprises the steps of: supplying a dielectricinto a dielectric injection space formed in the upper electrode; placinga substrate on the table; supplying a processing gas into the processingvessel; and changing the processing gas into the plasma between theupper electrode and the lower electrode, so as to perform a plasmaprocess to the substrate with the plasma, wherein the step of supplyingthe dielectric is performed for controlling a supply amount of thedielectric, such that in-plane uniformity of intensity of an electricfield of the plasma can be enhanced, as compared with the case in whichthe dielectric is not supplied into the dielectric injection space. 18.A plasma processing method using a plasma processing apparatus includingan upper electrode, a table constituting a lower electrode, a processingvessel configured for containing the upper electrode and the lowerelectrode therein, a first high frequency power source connected witheither one of the upper electrode and the lower electrode and used forgenerating plasma, and a second high frequency power source connectedwith the lower electrode and used for introducing ions present in theplasma, wherein the upper electrode and the lower electrode are arrangedto be opposed to each other, and wherein the plasma processing methodcomprises the steps of: supplying a dielectric into a dielectricinjection space formed in the upper electrode; placing a substrate onthe table; supplying a processing gas into the processing vessel; andchanging the processing gas into the plasma between the upper electrodeand the lower electrode, so as to provide a plasma process to thesubstrate with the plasma, wherein the step of supplying the dielectricis performed for controlling a supply amount of the dielectric, suchthat in-plane uniformity of intensity of an electric field of the plasmacan be enhanced, as compared with the case in which the dielectric isnot supplied into the dielectric injection space.
 19. A plasmaprocessing method using a plasma processing apparatus including an upperelectrode, a table constituting a lower electrode, a processing vesselconfigured for containing the upper electrode and the lower electrodetherein, and a first high frequency power source connected with thelower electrode and used for generating plasma, wherein the upperelectrode and the lower electrode are arranged to be opposed to eachother, and wherein the plasma processing method comprises the steps of:supplying a dielectric into a dielectric injection space formed in thelower electrode; placing a substrate on the table; supplying aprocessing gas into the processing vessel; and changing the processinggas into the plasma between the upper electrode and the lower electrode,so as to perform a plasma process to the substrate with the plasma,wherein the step of supplying the dielectric is performed forcontrolling a supply amount of the dielectric, such that in-planeuniformity of intensity of an electric field of the plasma can beenhanced, as compared with the case in which the dielectric is notsupplied into the dielectric injection space.
 20. A plasma processingmethod using a plasma processing apparatus including an upper electrode,a table constituting a lower electrode, a processing vessel configuredfor containing the upper electrode and the lower electrode therein, afirst high frequency power source connected with either one of the upperelectrode and the lower electrode and used for generating plasma, and asecond high frequency power source connected with the lower electrodeand used for introducing ions present in the plasma, wherein the upperelectrode and the lower electrode are arranged to be opposed to eachother, and wherein the plasma processing method comprises the steps of:supplying a dielectric into a dielectric injection space formed in thelower electrode; placing a substrate on the table; supplying aprocessing gas into the processing vessel; and changing the processinggas into the plasma between the upper electrode and the lower electrode,so as to perform a plasma process to the substrate with the plasma,wherein the step of supplying the dielectric is performed forcontrolling a supply amount of the dielectric, such that in-planeuniformity of intensity of an electric field of the plasma can beenhanced, as compared with the case in which the dielectric is notsupplied into the dielectric injection space.
 21. The plasma processingmethod according to any one of claims 17 to 20, further comprising thesteps of: reading data correlating a kind of each process with aninjection amount of the dielectric into the dielectric injection space,prior to the step of supplying the dielectric; and controlling theinjection amount of the dielectric into the dielectric injection space.22. A storage medium for storing therein a computer program for drivinga computer to execute a plasma processing method, wherein the plasmaprocessing method uses a plasma processing apparatus including an upperelectrode, a table constituting a lower electrode, a processing vesselconfigured for containing the upper electrode and the lower electrodetherein, and a first high frequency power source connected with thelower electrode and used for generating plasma, wherein the upperelectrode and the lower electrode are arranged to be opposed to eachother, and wherein the plasma processing method comprises the steps of:supplying a dielectric into a dielectric injection space formed in theupper electrode; placing a substrate on the table; supplying aprocessing gas into the processing vessel; and changing the processinggas into the plasma between the upper electrode and the lower electrode,so as to perform a plasma process to the substrate with the plasma,wherein the step of supplying the dielectric is performed forcontrolling a supply amount of the dielectric, such that in-planeuniformity of intensity of an electric field of the plasma can beenhanced, as compared with the case in which the dielectric is notsupplied into the dielectric injection space.
 23. A storage medium forstoring therein a computer program for driving a computer to execute aplasma processing method, wherein the plasma processing method uses aplasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, a processing vessel configured forstoring the upper electrode and the lower electrode therein, a firsthigh frequency power source connected with either one of the upperelectrode and the lower electrode and used for generating plasma, and asecond high frequency power source connected with the lower electrodeand used for introducing ions present in the plasma, wherein the upperelectrode and the lower electrode are arranged to be opposed to eachother, and wherein the plasma processing method comprises the steps of:supplying a dielectric into a dielectric injection space formed in theupper electrode; placing a substrate on the table; supplying aprocessing gas into the processing vessel; and changing the processinggas into the plasma between the upper electrode and the lower electrode,so as to perform a plasma process to the substrate with the plasma,wherein the step of supplying the dielectric is performed forcontrolling a supply amount of the dielectric, such that in-planeuniformity of intensity of an electric field of the plasma can beenhanced, as compared with the case in which the dielectric is notsupplied into the dielectric injection space.
 24. A storage medium forstoring therein a computer program for driving a computer to execute aplasma processing method, wherein the plasma processing method uses aplasma processing apparatus including an upper electrode, a tableconstituting a lower electrode, a processing vessel configured forcontaining the upper electrode and the lower electrode therein, and afirst high frequency power source connected with the lower electrode andused for generating plasma, wherein the upper electrode and lowerelectrode are arranged to be opposed to each other, and wherein theplasma processing method comprises the steps of: supplying a dielectricinto a dielectric injection space formed in the lower electrode; placinga substrate on the table; supplying a processing gas into the processingvessel; and changing the processing gas into the plasma between theupper electrode and the lower electrode, so as to perform a plasmaprocess to the substrate with the plasma, wherein the step of supplyingthe dielectric is performed for controlling a supply amount of thedielectric, such that in-plane uniformity of intensity of an electricfield of the plasma can be enhanced, as compared with the case in whichthe dielectric is not supplied into the dielectric injection space. 25.A storage medium for storing therein a computer program for driving acomputer to execute a plasma processing method, wherein the plasmaprocessing method uses a plasma processing apparatus including an upperelectrode, a table constituting a lower electrode, a processing vesselconfigured for containing the upper electrode and the lower electrodetherein, a first high frequency power source connected with either oneof the upper electrode and the lower electrode and used for generatingplasma, and a second high frequency power source connected with thelower electrode and used for introducing ions present in the plasma,wherein the upper electrode and the lower electrode are arranged to beopposed to each other, and wherein the plasma processing methodcomprises the steps of: supplying a dielectric into a dielectricinjection space formed in the lower electrode; placing a substrate onthe table; supplying a processing gas into the processing vessel; andchanging the processing gas into the plasma between the upper electrodeand the lower electrode, so as to perform a plasma process to thesubstrate with the plasma, wherein the step of supplying the dielectricis performed for controlling a supply amount of the dielectric, suchthat in-plane uniformity of intensity of an electric field of the plasmacan be enhanced, as compared with the case in which the dielectric isnot supplied into the dielectric injection space.